This invention relates to novel isomers of 3,4-dichloro-6-trifluoromethyltoluene, which is a known compound, and a method of preparing known and novel dichlorotrifluoromethyltoluenes. These isomeric compounds are useful as materials of some medicines and agricultural chemicals, and particularly as the materials of aminotrifluoromethyltoluenes (or methylaminobenzotrifluorides) which are of use as intermediates of some medicines such as tranquilizers and antiphlogistic anodynes and agricultural chemicals represented by herbicides.
It is known that 3,4-dichloro-6-trifluoromethyltoluene can be formed by the following reaction. (J. Fluor. Chem. (1981), 281-291) ##STR1##
However, in this process the conversion of 3,4-dichlorotoluene is only about 25%, and it is not easy to separate by-produced 3,4-dichloro-5-trifluoromethyltoluene. Besides, some portions of hydrogen fluoride and carbon tetrachloride react with each other to form trichlorofluoromethane as a by-product. We are aware of no literature showing dichlorotrifluoromethyltoluenes other than the above indicated two isomers.